Tiredness, stress, ill-health and poor diet will all reduce this ability further. BetterYou uses the most bio-available form of B12 (methylcobalamin) which is active in human metabolism. When sprayed under the tongue the vitamin enters the bloodstream directly. This avoids over-reliance on our inefficient digestive system. Absorption commences immediately. Boost B12 Oral Spray delivers 1200ug of this vital vitamin along with 40ug of chromium and 16mg of green tea extract with every dose (4 sprays). It's fast, it's convenient and it tastes great.